You may notice that sometimes you find more radars in the same area when a lot of people online, on weekends for example. It may look strange at first glance, since more explorers flying around.
Explanation to this is quiet simple.
If radar (or any other cosmic signature) was cleared in system A it respawns in System B (or even again in A). So, more radars cleaned around, more spawns in new systems, and possibly in area, where are you flying.
The main question people still debating where and when is the system B.
I have read and heard many speculations, rumors, theories , explanations and wild guesses how it works.
Just few examples of what you can find on forums:
Signature cleared in system A will respawn:
- in the same Constellation;
- in the range of X jumps from current system;
- the nearest system with the same Security Level;
- randomly in region;
and dozen other scenarios
I never saw a single comment on subject from CCP. And this is understandable. Want to farm plexes and radars? Find it yourself, if you are clever enough.
We run some tests in regions with limited number of systems in hi sec, as well as in low sec.
Well, respawning mechanics is not simple.
I have my own view on sites respawnings, but it is more guess rather than proved facts.
In any event, space is not static, and new cosmic signature can pop up in the system you just scanned 5 minutes ago.
On the last note: Down Time clears some signatures (72 hours old or so) and brings new ones.
In other words, plex in back water system will not be there forever.
Lets put aside complexity and presume common theory that radar (plex) cleared in system "A" respawns in system "B" imminently is good enough to be used as guidenence for our exploration venture.